Pneumatic-despatch-tube apparatus.



vI. w. LITGHFIELD. PNEUMATIC DESPATGH TUBE APPARATUS.

APPLICATION FILED SEPT.18,1905.

Patented June 1, 1909.

*orrrrnn srrrrns PATENT ISAAC W. LITOHFIELD, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO LAMSON CONSOLI- DATED STORE SERVIOE COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

PNEUMATIC-DESPATCH-TUBE APPARATUS.

To all whom it may concern:

Be it known that I, Isaac N. LrroHFiELD, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Pneumatic- Despatch-Tube Apparatus, of which the following is a specification.

My invention relates to improvements in pneumatic despatch tube apparatus and its object is to permit the passage of the carrier from the transit tube through a double-valve terminal without clogging or sticking owing to the improper action of the valves or back action of the vacuum. This object is attained by connecting the exhaust pipe and the delivery terminal with a normally open by-pass located between the inner and outer valves of said terminal and also connecting the said terminal above the outer valve with a valve-controlled passage to the atmosphere.

In the drawing, the figure represents a vertical longitudinal section of a double-valve terminal in which the exhaust tube O connects the transmission tube A with the terminal E by means of a by-pass H controlled by a hand operated valve G at a point between the inner valve F and the outer valve K of said terminal. The external chamber B surrounding one end of the transmission tube A is connected therewith by means of the peripheral ports D in the tube A and in turn connected with tube O. The by-pass H connects with the terminal E by means of the peripheral ports J and is normally open. The valve L operated by the finger L connects the terminal E with the atmosphere by means of the tube O. Air is supplied to the terminal E upon the opening of the said valve L through the channels N and M the ports M connecting the channel M with the terminal E. The carriers approaching the inner valve F pass through the said valve without clogging owing to the constant equalization of the pressure by means of the by-pass H connecting the transmission tube A and the terminal E, said valve F closing after the passage of the carriers which pass down the terminal E engaging the finger L thereby opening the valve L admittin air through said valve into said termina E, breaking the vacuum maintained therein through the by pass H and equalizing the Specification of Letters Patent.

Application filed September 18, 1905.

Patented June 1, 1909.

Serial No. 278,881.

pressure on said valve K and permitting the carriers to easily open the valve K and pass through and be discharged without clogging.

Having thus described the nature of my invention and set forth a construction embodying the same, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a pneumatic despatch tube apparatus, a transmission tube, a double valve delivery terminal connected thereto, an exhaust tube connected to said transmission tube, a connection between said exhaust tube and said terminal intermediate the in ner and outer valves to equalize the pressure on the inner valve, and means operated by a carrier and located in the path of travel thereof for admitting atmospheric pressure between the inner and outer valves of said terminal to relieve the pressure on the outer valve.

2. In a pneumatic despatch tube apparatus, a transmission tube, a double valve delivery terminal connected thereto, an exhaust tube connected to said transmission tube, a connection between said exhaust tube and said delivery terminal intermediate the inner and outer valves thereof and adapted to constantly equalize the pressure on said inner valve, and means for regulating said passage.

3. In a pneumatic despatch tube apparatus, a transmission tube, a double valve delivery terminal connected thereto, an exhaust tube connected to said transmission tube, a connection between said exhaust tube and said delivery terminal intermediate the inner and outer valves thereof and adapted to constantly equalize the pressure on said inner valve, means for regulating said passage, and means located in the path of travel of a carrier and operated thereby for admitting atmospheric pressure between the inner and outer valves of said terminals to relieve the pressure on the outer valve.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses, this 7th day of September A. D. 1905.

ISAAC W. LITOHFIELD. lVitnesses:

FRANK A. SEIB, GEORGE W. Emma. 

